Well my FFE is back to it's old dead 12V antics. Updated details in my 8-22-17 timeline post. This time the culprit seems to be the BECM Battery Energy (or Electronics depending on what reference you believe) Control Module. I may have gotten lucky and caught an intermittent problem. I reset the BECM fuse and all seemed ok again. We'll see if this issue comes back. I believe the BECM is in the upper battery pack. Does anyone know what it does?

Author:

triangles [ Wed Nov 07, 2018 8:21 am ]

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Re: Dead 12V battery then traction control freaks out

So I charged the 12V overnite unhooked from the car. And performed another draw down test. 1.32A. I didn't have time to see if the BECM was still the culprit. So I hooked the 12V back up and when I got in to go to work, I got the yellow wrench and battery depleted message shown below.Car had been parked a few days earlier with a 77% charge. I couldn't get a green ready to drive indicator So I plugged it in to charge and the car indicated it would take 4.6 hours to charge! 45 minutes later I get a charge complete text message and observe a 100% charge with the battery showing yellow and 1 mi indicated range on my phone. Going to read the DTCs at lunch and see if I can get her to drive. update: There was a boat load of DTCs all related to low 12V or lost communication (probably due to low 12v.) Nothing specific about the HV battery and no errors from the BECM. The car started and I could drive it but it was not happy at first. Started out with 1 mi on the GOM and just slowly went up from there as I drove. It got up into the 40's before it stopped rising. I took the pic below as it was rising.

Author:

triangles [ Fri Nov 16, 2018 11:52 am ]

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Re: Dead 12V battery then traction control freaks out

Should have posted this on November 12:Since my last post I figured out that pulling the F11 fuse while the car is on is what causes the car to freak out and think the HV battery is depleted when you next power on the car. I did some more trouble shooting and it looks like the BECM is indeed the culprit. Car still functions normally but when off the BECM causes a 1.3A load on the 12V battery. On November 8th I made an appointment for first thing in the morning November 13. I dropped it off after hours November 12. Last word from the dealer was on November 15 that diagnostics weren't conclusive. I take that to mean they are waiting on Ford to tell them what to do about the BECM. Does anyone know where the BECM is located in the car?

Not sure how I screwed up troubleshooting but it turns out my TCU is bad again. Not worth spending $700 for a 4th TCU that might last another year if I'm lucky. So I live without MFM, GO times, and Value Charging. Are the TCU's that shitty that they can't last much more than a year or is their something wrong with my car that's killing the TCU?

Author:

Dobrinia [ Sat Feb 23, 2019 2:29 am ]

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Re: Dead 12V battery then traction control freaks out

I have a similar story, TCU discharges the battery.Perhaps the fact is that the car is in Belarus (Europe) and AT & T is not available here...Yesterday there was an SSN error after the battery is low ...I charged a 12v battery and the error disappeared. I drove 100km and put the car in the garage. In the morning, the battery voltage was 12.9 volts, but the car did not start, SSN error.After charging the battery up to 15 volts, the car started up again without any errors.For this car you need a battery with a working voltage of more than 14 volts, and not 12 as in gasoline cars?

Author:

kalel14 [ Sun Feb 24, 2019 3:45 am ]

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Re: Dead 12V battery then traction control freaks out

Dobrinia wrote:

I have a similar story, TCU discharges the battery.

For this car you need a battery with a working voltage of more than 14 volts, and not 12 as in gasoline cars?

No. Mine starts with 12 V all the time.

Author:

rjhunter [ Wed Feb 27, 2019 3:50 pm ]

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Re: Dead 12V battery then traction control freaks out

Hi all. I'm new to this forum, so I want to first thank everyone who has taken the time to detail & discuss their issues and fixes. I have a 2014 FFE with a 33.5 KWh battery (replaced under warranty by previous owner in Sept 2017) with 50K miles on it. I have owned this car for 11 months, and I have been dealing with 12V battery issues since October. As described by others on this post, my 12V battery seems to randomly die (dropping down to ~9V) after sitting unplugged for 7-8 hours. Ford has replaced my 12V battery twice under warranty, and assured me that it was just a bad battery, and there is nothing wrong with my car. But I'm quite sure this has nothing to do with the 12V battery. I've noticed a pattern over the last 5 months that the 12V battery issues seem to correlate with MyFord Mobile issues (losing connection). I have to constantly pull the fuse on the Telematics Control Unit (fuse F1) to reset the TCU so that I can connect again. I recently used a Klein Tools model MM200 along with a Fuse Buddy 301M to measure current at the fuse level when the car is on and when the car is off. As per Triangles advice, I was sure to measure after 40 minutes as well. What I found was that all units that I tested (I only measured fuses that were 10A or lower) read zero amps when the car was shut down. But the TCU never shut off. It constantly bounced from 0.03A up to 1.3A, but mostly sitting round around 0.04A. I pulled the TCU fuse and left it out. It's been 3 days now, and so far, I have had no issues with the 12V battery.

Author:

Magnetoreluctance [ Tue Mar 05, 2019 7:20 am ]

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Re: Dead 12V battery then traction control freaks out

Just wanted to add my experience to the thread. '13 FFE, just like triangles otherwise, but fortunately I've only had two instances of a dead 12 volt.

When it happened last September, my dealer charged me ~$700 to replace the TCU with a new one. I'm not thrilled that the problems continue, but I strongly suspect the TCU is still the culprit based on my latest incident.

So my car is currently getting a ceramic coating and thus was left unplugged overnight at the detail shop while it cured. I checked on the car with MFM late last night just being curious, and here we are this morning the car is dead after sending me a text. I'm not going to try and do further diagnosis at this point. It sounds like the solution is just to live without MFM and unplug the TCU. While its nice to have, I don't want to deal with this as an ongoing problem. If there are further issues, I will try and remember to come back to this thread.